Before surrendering to police in Belfast, the 65-year-old Adams declared his innocence in the death of 37-year-old Jean McConville, who was kidnapped in front of her 10 children, shot in the back of the head and secretly buried.

The IRA did not admit to killing her until 1999, a year after the Good Friday Agreement that ended three decades of bloody strife in Northern Ireland. She had been listed as among 16 people classified as "disappeared" until her remains were found on an Irish beach in 2003.

In a statement, Adams described his appearance as a voluntary, prearranged interview. He announced last month that he would talk to police about the case after an IRA leader in the 1970s was arrested on charges of aiding and abetting McConville's murder.

"I believe that the killing of Jean McConville and the secret burial of her body was wrong and a grievous injustice to her and her family," Adams said. "Well-publicized, malicious allegations have been made against me. I reject these.

"While I have never disassociated myself from the IRA and I never will, I am innocent of any part in the abduction, killing or burial of Mrs McConville."

The IRA, the armed affiliate of the Sinn Fein political party, suspected McConville of feeding information to the British military stationed in Northern Ireland. An official inquiry eventually cleared her name.

No one has been charged directly with murdering McConville, though several related arrests have been made in the past few weeks.

The arrests of Adams and the others stem from an oral history project at Boston College documenting "the Troubles," the violent, 30-year battle between Protestants and Catholics over whether Northern Ireland would remain aligned with Britain or become part of the Republic of Ireland.

Researchers taped confessional interviews with former loyalist and republican paramilitaries, and two IRA operatives implicated Adams in McConville's abduction and slaying.

The tapes were supposed to remain private until their deaths, but Northern Ireland officials persuaded U.S. courts to release some material because of the serious crimes discussed.

Sinn Fein deputy leader Mary Lou McDonald called Adams' arrest "politically motivated and designed to damage Gerry Adams and Sinn Féin" ahead of local and European elections, the Irish Times reported.